Struct CoordinationGuard 

pub struct CoordinationGuard { /* private fields */ }

Guard type that releases leadership when dropped.

Holds the advisory lock key and the actual database connection that acquired the lock. This is critical because PostgreSQL advisory locks are session-scoped: the unlock must happen on the same connection that acquired the lock.

Lock Release Behavior

The guard attempts to explicitly release the advisory lock when dropped:

• Multi-threaded runtime: Uses block_in_place to synchronously release the lock before the guard is fully dropped.

• Single-threaded runtime: Spawns a task to release the lock asynchronously. This task may not execute before process shutdown, in which case the lock is released when the PostgreSQL session ends (connection closes).

PostgreSQL Session-Scoped Locks

PostgreSQL advisory locks acquired with pg_try_advisory_lock are session-scoped and automatically released when the database connection closes. This provides a safety net: even if explicit unlock fails or is skipped, the lock will be released when:

• The connection is returned to the pool and recycled
• The connection pool is shut down
• The database connection times out

For production deployments, configure appropriate connection pool idle timeouts to ensure timely lock release on ungraceful shutdown.

Trait Implementations

impl Debug for CoordinationGuard

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for CoordinationGuard

fn drop(&mut self)

Executes the destructor for this type.